A nanoporous membrane based impedance sensing platform for DNA sensing with gold nanoparticle amplification

Nucleic acids based detection has become increasingly important for biomedical diagnostics, environmental monitoring and food screening. In this paper, a nanoporous alumina membrane based impedance sensing platform with gold nanoparticle tags amplification was developed for DNA sensing. Single stranded DNA (ssDNA) probes were first covalently immobilized in nanopore walls via chemical linkers. DNA hybridization in the nanopores induced blockage in the nanopores, which could be detected by electrochemical impedance spectroscopy (EIS). The blockage signal could be further amplified by gold nanoparticles (AuNPs) conjugation and silver catalytic deposition method to reach a limit of detection (LOD) of 50 pM. This platform is promising for simple, rapid and sensitive DNA detection.